var speed=10;
demo2.innerHTML=demo1.innerHTML;
function Marquee(){
    if(demo2.offsetTop-demo.scrollTop<=0){
        demo.scrollTop-=demo1.offsetHeight;
    }
    else{
        demo.scrollTop++;
    }
}
var MyMar=setInterval(Marquee,speed);
demo.onmouseover=function() {clearInterval(MyMar)};
demo.onmouseout=function() {MyMar=setInterval(Marquee,speed)};
